[ale] End of Time, *nix Time

Tue Apr 28 08:25:44 EDT 2026

Quite frankly at the age of 75, diabetic,  three heart attacks and only 26%
of my heart capacity left I do not think I have to worry about this.

But it was fun reading about it anyway.😜

On Sat, Apr 25, 2026, 23:54 Bob Toxen via Ale <ale at ale.org> wrote:

> I've just uploaded the new and improved code to my web site so please
> download again and email just me (transam at VerySecureLinux.com) if you
> get any more compiler warnings or strange results to be addressed.
>
> This new version improves the messages to be less cryptinc but the
> program does assume you know something about how time is handled in
> *nix.  The short answer is that if you have the old signed 32-bit
> time_t type then the largest year you will see will be 2038 in
> output of the form "Day-of-week Month Day ##:##:## Year".
>
> If you get a reference from Hitchhiker's Guide to the Galaxy then
> you have the new 64-bit time_t type and you should be good for the
> next two billion years.
>
> Please send me comments to address.
>
> Bob
>
> On Sat, Apr 25, 2026 at 02:38:03PM -0400, Jeff Lightner via Ale wrote:
> > This made me think of my annoyance at logs for some apps that did
> > epoch timestamps.  More than once I wrote a script to calculate human
> > readable time as it displayed lines from such logs.  I???m sure there
> > are some who can eyeball epoch and convert it mentally to star date and
> > other clock/calendar systems but I wasn???t one of them.  > Which also
> > made me think of the fact that some logs are in UTC rather than local
> > time zone time.  At least I could do that conversion in my head.
>
> > Back when we tested for Y2K bugs many of us who were UNIX admins
> > also tested for future dates against the 32 bit limit and other factors.
> > I often thought it odd that most UNIX platforms already did 64 bit
> whereas
> > many Linux distros didn???t even if they were on a 64 bit processor.
>
> > From: Ale <ale-bounces at ale.org> On Behalf Of Ron via Ale
> > Sent: Saturday, April 25, 2026 1:29 PM
> > To: ale at ale.org
> > Cc: Ron <ron at bclug.ca>
> > Subject: Re: [ale] End of Time, *nix Time
> >
> >
> >
> > Bob Toxen via Ale wrote on 2026-04-24 19:43:
> >
> >   # Download this program:
> >   wget http://verysecurelinux.com/xtime.c
> >   # Compile:
> >   make xtime
> >   # Run:
> >   ./xtime -q
> >
> > I downloaded an compiled this.
> >
> > Lots of warnings when running `make`, but it compiled.
> >
> > What am I to make of the output? I can make no sense of it.
> >
> >
> >
> > $ ./xtime -q
> > Copyright (c) Bob Toxen 2026.  All rights reserved.
> >
> > This program will analyze your *nix for the well-known bug if the
> > seconds since 01/01/1970 exceeds a signed 32 bit (4-byte) integer.
> > If it outputs abnormal output for years beyond 2038 then your computer
> > will fail at that time, about 12 years from now.
> >
> > Many *nix systems were fixed decades ago so that this variable became
> > an unsigned 32-bit int, which can keep time until 2106.
> > More recently most systems went to a signed 64-bit int.
> >
> > Note that most Unix and Linux distributions corrected the time
> > problem by approximately 2014 to work until 2106 (using an unsigned
> > 32-bit number) or well beyond if using a 64-bit number but maybe the code
> > will fail before the largest 64-bit signed (292,271,022,989 years)
> > or unsigned number is exceeded.
> >
> >
> > If it is not fixed in your version, well, good luck.
> >
> > sizeof char=1, sizeof short=2, sizeof int=4, sizeof long=8, sizeof long
> long=8, sizeof time_t=8
> >
> > Current years and seconds since the epoch: 56 1777137911
> >   seconds/year:31536000, seconds/year including leap year:31557600,
> delta seconds:21600, delta hours:6
> >
> > Biggest   signed 4-byte long: years inc=            0, years in the
> future=           11, Mon Jan 18 19:14:07 2038
> > Biggest unsigned 4-byte long: years inc=            0, years in the
> future=           79, Sat Feb  6 22:28:15 2106
> >
> > Time: years inc=            1, years in the future=   2147437525, Wed
> Jun 12 15:25:11 2147483647
> >
> > Welcome to the Restaurant at the end of the universe.  Hello, your
> Majesty.
> >
> > Biggest   signed 8-byte long: years inc=            0, years in the
> future= 292271022988,
> > ERROR: Invalid seconds since Epoch in localtime
> > Error code: Value too large for defined data type
> >
> > Biggest unsigned 8-byte long: years inc=            0, years in the
> future=          -56, Wed Dec 31 15:59:59 1969
> >
> >
> >
>
> > _______________________________________________
> > Ale mailing list
> > Ale at ale.org
> > https://mail.ale.org/mailman/listinfo/ale
> > See JOBS, ANNOUNCE and SCHOOLS lists at
> > http://mail.ale.org/mailman/listinfo
>
> _______________________________________________
> Ale mailing list
> Ale at ale.org
> https://mail.ale.org/mailman/listinfo/ale
> See JOBS, ANNOUNCE and SCHOOLS lists at
> http://mail.ale.org/mailman/listinfo
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mail.ale.org/pipermail/ale/attachments/20260428/ba2b1ecb/attachment.htm>